Abstract
AIM: Cardiovascular diseases display strong sex differences. Angiotensin II (AngII) is implicated in this process. The ubiquitously expressed enzymatic beta subunit of calcineurin (PPP3CB), a serine/threonine phosphatase, can mediate pathological effects of AngII in the heart. Our aim was to explore the role of calcineurin in sex-dependent AngII-mediated vascular changes. METHODS: We used female and male mice with a global PPP3CB knockout that were treated with AngII for 4 weeks as an in vivo model. For validation experiments and investigation of signaling pathways, primary aortic vascular smooth muscle cells (aVSMCs) isolated from respective female and male WT mice were utilized. RESULTS: AngII-induced increase in blood pressure was less pronounced and not calcineurin-dependent in female compared to male mice with no changes in media thickness or lumen area. Wire and pressure myography showed an AngII-induced calcineurin-dependent endothelial dysfunction in males but not in females. In aVSMCs from female mice, AngII did not influence wound closure or cell proliferation as was detectable in aVSMCs of male mice. As an underlying mechanism for these sex differences in long-term AngII effects, RNA-seq data and IPA revealed differentially regulated genes and pathways, involving extracellular matrix components, calcineurin, Ctgf, Egfr, and Tgfb1. Downstream of Egfr, we identified sex-dependent activation of PKC signaling in male and ERK/MAPK signaling in female as mediators of Ctgf expression. CONCLUSION: Overall, the relevance of AngII-calcineurin signaling for pathophysiological effects in the vasculature differs between female and male mice, suggesting both sexes require customized prevention and treatment strategies for cardiovascular disorders.